Fin for water skis



y 4, 1963 G. H. MAY 3,089,157

' FIN FOR WATER SKIS Filed Aug. 11. 1960 FIG.2 FIG.3

INVENTOR. GORDON H. MAY

United States Patent @ffiee Patented May 14, 19%3 assess; Fifi FUR WAT RSKIS Gordon H. May, 1923 tiarnden Ave, San lose, Calif. Filed Aug. it,was, Ser- No. sasss 3 Claims. (til. 9-616) The present invention relatesto a fin for a water ski and more particularly to a fin for stabilizinga water ski in a plurality of directions.

The commonly used slalom Water ski has a knife-like fin which extends upto 4 /2 inches below the lower surface of the ski. This type finstabilizes the ski in a lateral direction for steering under smoothskiing conditions. However, in rough water the ski may bounce and pullthe fin out of the water, thus leaving the ski with no steering purchasein the water. This type fin also offers somewhat of a hazard to swimmersor fallen skiers because of its deep, knife-like silhouette.

The object of the present invention is the provision of fin whichprovides both lateral and vertical stability for a water ski with aminimum depth silhouette.

In the present invention a hollow, generally U-shaped fin is providedfor attachment along the lower centerline of a water ski. A continuousflow of water courses through the hollow interior of the fin and resistsboth vertical and lateral movement of the ski while providing excellentsteering properties for the ski.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a water ski incorporating the fin of thepresent invention;

FIG. 2 is an elevation view of the present fin; and

FIG. 3 is an end view of the fin of FIG. 2.

The fin 10 of the present invention is illustrated in FIG. 1 inoperating position on the lower, rear centerline of a conventionalslalom water ski. An unobstructed channel 11 through the interior of thefin is shown as aligned with the longitudinal axis of the ski to permitthe flow of water through the fin as the ski rides along the surface ofthe water.

Referring to FIGS. 2 and 3, the fin of the present invention has anelongated web section 12 which is generally U-shaped in cross-section.The lateral edges of the web are bent outwardly in opposite directionsapproximately normal to the Web to define thin flanges 13 and 14. Theleading edge 15 of the web is tapered rearwardly away from the flangesfor streamlining elfect, while the trailing edge 16 of the web may beperpendicular to the flanges. Spaced openings 17 are provided along thelength of each flange to permit attachment of the fin to a ski by anysuitable securing means, such as screws, bolts, etc. The web comprisesthin parallel side sections which provided lateral stability and anarcuate section joining the lower ends of the side sections andproviding for vertical stability.

The flow of water through the channel defined by the web of the presentfin and the lower surface of the attached ski provides both vertical andlateral stability for the ski. The fin holds the ski in contact with thesurface of the water and resists upward movement to the rear of the ski,so that the ski is under the control of the skier at all times. The fiowof water through the channel in the fin not only holds the skivertically, but also provides excellent steering properties for the ski,even though the depth of the present fin in only approximately half thatof the conventional slalom ski fin. The low silhouette makes forconvenient storage and carrying of the ski, and with the tapered leadingedge, greatly reduces the safety hazard to swimmers or fallen skiers incase of accident.

The web of the present invention is illustrated as U-shaped, but otherunobstructed concave shapes, such a V, semicircle, etc., may be used ifdesired. While the present fin has been illustrated with a slalom(single) ski it is equally applicable to double skis, and may be usedwith other similar surface-riding craft, such as surfboards, etc.

Obviously many modifications and variations of the present invention arepossible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

What is claimed as my invention is:

l. A stabilizing fin for providing both vertical and lateralstabilization of a water ski, the fin comprising an elongated hollowmember adapted to be aligned with the longitudinal axis of the ski themember including thin fiat mounting means, means for providing lateralstability including a pair of elongated spaced generally parallel sidesections joined to the fin mounting means along longitudinal edgesthereof and depending therefrom and means for providing verticalstability including an armate section joined to both side sections alonglongitudinal edges thereof spaced from and parallel to the mountingmeans, the arcuate section and the side sections defining a straightunobstructed channel throughout the length of the fin permitting aconstant flow of water parallel to the longitudinal axis of the ski.

2. A stabilizing fin for providing both vertical and lateralstabilization of a water ski, the fin comprising an elongated hollowmember adapted to be aligned with the center line of the ski, the memberincluding:

thin flat mounting means adapted to be received flush against the lowersurface of the ski;

means for providing lateral stability including a pair of thin elongatedplanar side sections positioned generally parallel to each other andspaced at short distance apart, each side section having onelongitudinal edge secured to the mounting means and extendingapproximately normal thereto to resist lateral displacement of the ski;and

means for providing vertical stability including a deeply curved sectionjoining the remaining longitudinal edges of the side sections, thecurved section and the side sections forming a straight unobstructedchannel throughout the length of the fin permitting a constant flow ofWater parallel to the longitudinal axis of the ski and resistingvertical displacement of the ski.

3. A stabilizing fin for a water ski, comprising: thin flat mountingmeans;

planar means for providing lateral stabilization connected to themounting means; and

arcuate means for providing vertical stabilization connected to theplanar means and removed from the mounting means.

the planar means and the arcuate means combining to form a straightchannel extending the length of the fin for conducting an unobstructedflow of Water parallel to the longitudinal axis of a ski.

References Cited in the file of this patent UNITED STATES PATENTS2,462,450 Wilson Feb. 22, 1949 2,940,091 Fifer June 14, 1960 3,025,539Kincaid Mar. 20, 1962 FOREIGN PATENTS 6,574 Great Britain 1888 544,239Great Britain Apr. 2, 1942

1. A STABILIZING FIN FOR PROVIDING BOTH VERTICAL AND LATERAL STABILIZATION OF A WATER SKI, THE FIN COMPRISING AN ELONGATED HOLLOW MEMBER ADAPTED TO BE ALIGNED WITH THE LONGITUDINAL AXIS OF THE SKI THE MEMBER INCLUDING THIN FLAT MOUNTING MEANS, MEANS FOR PROVIDING LATERAL STABILITY INCLUDING A PAIR OF ELONGATED SPACED GENERALLY PARALLEL SIDE SECTIONS JOINED TO THE FIN MOUNTING MEANS ALONG LONGITUDINAL EDGES THEREOF AND DEPENDING THEREFROM AND MEANS FOR PROVIDING VERTICAL STABILITY INCLUDING AN ARCUATE SECTION JOINED TO BOTH SIDE SECTIONS ALONG LONGITUDINAL EDGES THEREOF SPACED FROM AND PARALLEL TO THE MOUNTING MEANS, THE ARCUATE SECTION AND THE SIDE SECTIONS DEFINING A STRAIGHT UNOBSTRUCTED CHANNEL THROUGHOUT THE LENGTH OF THE FIN PERMITTING A CONSTANT FLOW OF WATER PARALLEL TO THE LONGITUDINAL AXIS OF THE SKI. 